The invention relates to a pick-up element in a stringed instrument for converting a vibration generated in at least one string into an electrical signal, comprising a pick-up section underneath each string, which pick-up section comprises at least three magnetic poles, each magnetic pole exerting a magnetic force on the string, the magnetic poles being placed in a row underneath the string, at least one of the poles comprising a first bolt which can be moved in the direction of the string and the magnetic poles deriving their magnetic action from permanent magnets positioned between the poles.
Such a pick-up element is disclosed by WO 82/04156. The latter describes a pick-up element for an electric guitar which comprises, for each string, a section which converts the mechanical vibrations of the string into an electrical signal. The electrical signal is combined with the signals from the other strings and, after amplification in an electrical amplifier, is fed to a loudspeaker. The mechanical vibration is converted into an electrical signal by means of magnetic coupling between the string and the poles of permanent magnets incorporated in the pick-up element. A coil wound round the permanent magnets converts the varying magnetic field due to the string vibrating in the vicinity of the magnets into an electrical voltage which mirrors the vibration. One of the poles comprises a magnetisable bolt which can be moved in the direction of the string and which is in magnetic contact with the permanent magnets. In this way, the intensity of the magnetic coupling and, therefore, the amplitude of the electrical signal generated can be regulated for each string by rotating the bolt in the pick-up element.
A disadvantage of the known pick-up element is that, once it has been mounted in a fixed position underneath the strings, only the intensity of the magnetic coupling for each string can be regulated. Regardless of the position of the bolt in the pick-up element, which bolt can be moved only by a small amount, the frequency spectrum pick-up is virtually the same. The timbre pick-up for each string consequently remains the same. The frequency spectrum picked up can be altered only by displacing the entire element in the longitudinal direction of the string. Thus, an element placed underneath the centre of the strings will give a much "richer" sound than one placed underneath the ends of the strings. Displacement of the entire element underneath the strings is, however, impractical. In practice, the timbre is therefore adjusted by means of high-pass and low-pass filters in the electrical amplifier. The timbre, however, can no longer be adjusted for each individual string by these means.